Electrical jack



July 17, 1962 FRANTZ ET AL 3,045,078

-ELECTRICAL JACK Filed 0012. 2, 1958 ELIE-.l I 20 34 32 C) I6 40 v 52 INVENTORS NICHOLAS FRANTZ BY STANLEY GLOVIAK FINN G. OLSEN A'r'roanzv United States Patent ()fifice 3,045,078 Patented July 17, 1962 3,045,078 ELECTRICAL JACK Nicholas Frantz, Skokie, and Stanley Gloviak, Westchester, 111., assignors to Carter Parts Company, Skokie, Ill., a corporation of Illinois Filed Oct. 2, 1958, Ser. No. 764,936

9 Claims. (Cl. 200-511) The present invention relates to electrical jacks, and more particularly to improvements in an electrical jack or a jack and switch unit, which is characterized by its small dimensions and its ability to retain accurate dimensions between contact elements thereof after extended usage.

The disclosed embodiment of the present invention is intended to be used in conjunction with a plug having a tip connected to an internally extending conductor and having an electrically conductive ring axially spaced from the tip. The jack is of the type having two spring contact elements, one adapted to be engaged by the plug tip and the other to be engaged by the plugring. In order to conserve weight and space, it has been increasingly necessary to restrict the size of the jack which in turn has created additional problems relating to preventing undesirable short circuits occurring within the jack which may be injurious to other electrical components in the circuit into which the jack is installed. This condition may not exist when the jack is new, but it can develop through usage by deformation of the rather small spring contact elements. 7

By way of example, it is essential that the axial dis tance between the contact portions of the tWo spring contact elements be kept substantially constant, or at least that the axial distance between these portions is not diminished by deformation of one or both of the spring contact elements. In the event that these portions are deflected toward one another, it is possible that the plug when being inserted will allow a short circuit to occur momentarily between the two spring contact portions. As pointed out above, this may be injurious to other components in the circuit or where sound equipment is employed, it may result in undesired noise in the circuit. It is recognized that this condition can be overcome by lengthening the electrical plug and spacing the contact elements farther apart, but this defeats the purpose of trying to restrict the size and weight of the electrical apparatus.

It is the principal object of the present invention to overcome the shortcomings of the prior art devices and to provide an electrical jack which is constructed and arranged so that the axial dimensions between the contact portions of the spring contact elements will not diminish after extended usage of the jack.

It is another object of the present invention to provide an electrical jack of the foregoing character which is constructed and arranged so that its various elements are secured or interlocked in place in a manner most effective for assembling the same and from which optimum results of the jack can be obtained in use.

It is still another object of the present invention to provide an improved electrical jack of the foregoing character wherein a dielectric molded plastic body is employed for mounting the various spring contact elements in a predetermined spaced relation, said body being constructed and arranged to assure that such elements will remain in their mounted positions in use.

It is still another object of the present invention to pro vide an electrical jack and switch unit which is constructed It is still another object of the present invention to provide a spring contact element for use in an electrical jack or jack and switch combination, said spring'contact element being constructed and arranged so that it will not be elongated as a result of repeated insertions and removals of a plug into or from the jack or jack and switch combination.

Other objects of this invention will appear in the following description and appended claims, reference being had to the accompanying drawings forming a part of this specification wherein like reference characters designate corresponding parts in the several views.

In the drawings:

FIGURE 1 is a front elevational view illustrating an electrical jack and switch unit embodying the present invention;

FIGURE 2 is a longitudinal sectional view of the electrical jack and switch unit illustrated in FIGURE 1;

FIGURE 3 is an end elevation as viewed from the right of FIGURE 1; and

FIGURE 4 is a schematic diagram illustrating the electrical circuits that can be made with the electrical jack and switch unit illustrated in FIGURES 1 to 3, inclusive.

Before explaining the present invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and arrangement of parts illustrated in the accompanying drawings, since the invention is capable of other embodiments and of being practiced or carried out in various ways. Also, it is to be understood that the phraseologly or terminology employed herein is for the purpose of description and not of limitation.

Referring now to the drawing, a more detailed description of the present invention will be given. The electrical jack and switch unit 10 has an insulator 12 which is made from a moldedphenolic and has a central opening 14 with slots 16 formed in the walls of the opening 14. The one end of the insulator 12 has two diametrically opposed transverse notches 18 extending between the opening 14 and the outer surface. Straddling the end of the insulator .12 and fitting into the notches 1-8 are the spring contact the notches 18. The one side of element 20 extends externally of the insulator 12 and has an apertured end 24 to Which an electric conductor can be connected. The other side of element 20 extends into the opening 14, initially converging toward the axis of the opening 14, as at 26, and then diverging from the axis of opening 14, as at 28. The divergent portion 28 then has a reverse bend, as at 30, followed by portion 32 which extends back toward the axis of opening 14 terminating in a contact portion 32 which has a radially outwardly turned terminal end 34.

It is also to be observed that the intermediate portion of spring contact element 20 is of sufficient width so that 'by the alternate numbers 26 to 34, inclusive, forms the spring contact arm that is engaged by the mating plug (not shown). The side segments 36 fit into the slots 16 in the inner wall or insulator 12. This position is obtained by sliding the segments into slots 16 from the left end of the insulator as viewed in FIGURES 1 and 2.

'When fully inserted only the free end of spring contact arm 20 can be moved and the contact element 20 is retained in a very stable position;

The other spring contact element 22 is mounted on the insulator 12 in the same manner as spring contact element 20. It also has an apertured end portion 38 to which an electrical conductor can be connected and it has side segments 40 which fit into the slots 16. The spring contact element 22 differs in that it has a relatively long arm portion having a radially inwardly projecting contact surface 42 followed thereafter by an outwardly extending terminal portion 44. The contact portion 42 is adapted to seat against the tip of the associated electrical plug (not shown), while the contact portion 32 of the spring contact element 20 is adapted to seat against the ring or sleeve of the aforesaid electrical plug (not shown). Thus, the spring contact element 20 may be referred to as the tip spring and the spring contact element 22 as the ring spring.

The insulator 12 has formed as an integral part there of a leg 46 on which is mounted a shunt terminal 48 by means of a rivet 50. The shunt terminal 48 has a contact 52 adapted to be engaged by the terminal end of the spring contact element 22 so as to form a normally closed connection therebetween. Thus, in the illustrated embodiment, the entire unit may be identified as a jack and switch since until the plug element is inserted into the jack, a normally closed connection is provided between the spring contact element 22 and the shunt terminal 48. When the electrical plug (not shown) is inserted into the jack, the switch or elements 22 and 48 will be opened. The portions of the plug which normally contact the surfaces 32 and 42 of contact elements 20 and 22 will then cooperate with the plug to form closed jack circuits.

The spring contact elements 20 and 22 are held against displacement from the insulator 12 by the annular insulating element 54 which seats on the one wall of insulator 12 and blocks the open side of the notches 18 in which the spring contact elements 20 and 22 are fitted. Also, the mid-portions of these elements which straddle the insulator 12 are in a common plane thereby assuring that the minimum overall length of the jack will be used.

Positioned above the insulating element 54 is the sleeve 56 which has a clamp terminal 58 integrally attached as at 69. The clamp terminal 58 has tongues 62 which are clinched under the shoulders 64 of the insulator 12, thereby clamping the insulating element 54 to the insulator 12. The clamp terminal 58 has a terminal 66 to which an electric conductor can be connected providing a ground for the electrical jack 10.

Referring to FIGURE 4, a schematic diagram illustrates the electrical components of the electrical jack and switch unit illustrated in FIGURES l to 3, inclusive. It will be observed that the sleeve 56 is directly connected to the ground 66. The spring contact element 22 forms a normally closed circuit with the shunt terminal 48. The spring contact element 20 is adapted to engage the plug (not shown) at the contact portion 32 while the other spring contact element 22 is adapted to engage the tip of the plug (not shown) at the contact surface 42.

One of the features of the present invention is the manner in which the spring contact element 20 is constructed and arranged. By virtue of the reverse bend 30, the contact element will not become elongated by virtue of long usage, and if there should be a change, the axial distance between the contact portion 32 and 42 will not be diminished, but instead, will be lengthened. Thus, if the terminal end portion of the spring contact element 20 should flatten out, the end 34 will be elongated toward the left end of the jack. Likewise, if the contact element '22 should be flattened out at its contact portion 42, its terminal end will be lengthened toward the right as seen in FIGURE 2. Thus, the spacing between the two contact portions will not diminish but if any change occurs, it will be lengthened. This assures that there will not be a short circuit between the two spring contact elements 20 and 22 while the plug (not shown) is being removed from or inserted into the jack.

This feature of the invention applies equally well whether a simple jack is employed wherein the shunt terminal 48 would be eliminated, or where a jack and switch arrangement is employed such as is shown in FIGURE 2.

Having thus described our invention, we claim:

1. A combination electrical jack and switch comprising an insulator having a central axial opening and an integral leg projecting from one end, the other end of said insulator having two spaced notches therein extending in a generally radial direction between the inner and outer surfaces of said insulator; a shunt terminal mounted on the free end of said leg and having a contact portion; a first spring contact element with an intermediate portion fitted into one of said notches, an outer end portion projecting from said insulator to form an electric terminal and an inner end portion extending in a generally axial direction toward said shunt terminal and having its free end normally engaging said cont-act portion, said inner end portion having near its free end a radially inwardly projecting segment adapted to be engaged by a plug inserted through said insulator and thereby to separate the inner end portion from said contact portion; a second spring contact element having an intermediate portion fitted into the other of said notches, an outer end portion projecting from said insulator to form an electric terminal and an inner end portion extending in agenerally axial direction through the opening in the insulator and thereafter having a radially inwardly turned reverse bend with the free end being deflected radially outward to form inward thereof a segment adapted to be engaged by said plug, the segment on the second spring contact element being axially spaced from the segment on the first spring contact element; an apertured insulating element overlying said other end of the insulator with the aperture in registry with said opening; and a sleeve positioned on said insulating element in registry with said aperture and carrying a ground terminal clamp, the latter clamping said insulator and insulating element together.

2. A combination electrical jack and switch as defined in claim 1 wherein said insulator is a one piece molded dielectric plastic body.

3. A combination electrical jack and switch as defined in claim 1 wherein said insulator has shoulders on opposite sides and said clamp has tongues deflected over said shoulder-s for rigidly clamping the insulator to the insulating element.

4. A combination electrical jack and switch as defined in claim 1 wherein the first spring contact element has two spring fingers, one on each side of said inner end portion, said fingers being deflected into engagement with the inner surface of said insulator to help retain the spring element in place.

5. A combination electrical jack and switch as defined in claim 1 wherein the second spring contact element has two spring fingers, one on each side of said inner end portion, said fingers being deflected into engagement with the inner surface of said insulator to help retain the spring element in place.

6. A combination electrical jack and switch comprising an insulator having a central axial opening; a shunt terminal mounted on one end of said insulator; a first spring contact element with an intermediate portion fitting over the other end of said insulator, an outer end portion projecting from said insulator to form an electric terminal and an inner end portion extending in a generally axial direction toward said shunt terminal and having its free end normally engaging said contact portion, said inner end portion having near its free end a radially inwardly projecting segment adapted to be engaged by a plug inserted through said insulator and thereby to separate the inner end portion from said contact portion; a second spring contact element having an intermediate portion in a common plane with the first-named intermediate portion and fitted over the other end of said insulator in circumferentially spaced relation from the first spring contact element, an outer end portion projecting from said insulator to form an electric terminal and an inner end portion extending in a generally axial direction through the opening in the insulator and thereafter having a radially inwardly turned reverse bend with the free end being deflected radially outward to form inward thereof a segment adapted to be engaged by said plug, the segment on the second spring contact element being axially spaced from the segment on the first spring contact element; tan apertured insulating element overlying said other end of the insulator with the aperture in registry with said opening; and a sleeve positioned on said insulating element in registry with said aperture and carrying a ground terminal clamp, the latter clamping said insulator and insulating element together.

7. In an electrical jack adapted to receive a plug having an electrically conductive tip and an electrically conductive ring axially spaced from said tip, an insulator having an axial passageway, a spring contact element having an intermediate portion mounted on an end of said insulator with one end of the contact element extending from said insulator to serve as a terminal and the other end projecting through said passageway, said other end extending in a direction away from said insulator end, said other end having a protrusion adapted to be engaged by said tip, a second spring contact element having an intermediate portion in a common plane with the first-named intermediate portion and mounted on the other end of said insulator with one end extending from said insulator to serve as a second terminal and the other end projecting throughsaid passageway and having an inturned reverse bend, the reversed portion having an inward protrusion spaced axially of said passageway from said first protrusion and adapted to be engaged by said conductive ring when the tip is in engagement with the protrusion of the first contact element.

8. In an electrical jack as defined in claim 7 wherein 6 the intermediate portions of the first and second spring contact elements are in a common plane.

9. An electrical jack adapted to receive a plug having an electrically conductive tip and an electrically conductive ring axially spaced from said tip, said jack com trusion adapted to be engaged by said tip, a second spring I contact element having an intermediate portion in a. common plane with the first-named intermediate portion and mounted on the other end of said insulator with one end extending from said insulator to serve as a second terminal and the other end projecting through said passageway and having an 'inturned reverse bend, the reversed portion having an inward protrusion spaced axially of said passageway from said first protrusion and adapted to be engaged by said conductive ring when the tip is in engagement with the protrusion of the first contact element, an insulating element positioned over the intermediate po'ntions of said first and second contact elements, and means holding said insulator and insulating elements together.

References Cited in the file of this patent 

